The scsi driver function sd_read_block_characteristics() always calls
disk_set_zoned() to a disk zoned model correctly, in case the device
model changed. This is done even for regular disks to set the zoned
model to BLK_ZONED_NONE and free any zone related resources if the drive
previously was zoned.
This behavior significantly impact the time it takes to revalidate disks
on a large system as the call to disk_clear_zone_settings() done from
disk_set_zoned() for the BLK_ZONED_NONE case results in the device
request queued to be frozen, even if there are no zone resources to
free.
Avoid this overhead for non-zoned devices by not calling
disk_clear_zone_settings() in disk_set_zoned() if the device model
was already set to BLK_ZONED_NONE, which is always the case for regular
devices.
Reported by: Brian Bunker <brian@xxxxxxxxxxxxxxx>
Fixes: 508aebb80527 ("block: introduce blk_queue_clear_zone_settings()")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Damien Le Moal <dlemoal@xxxxxxxxxx>
Reviewed-by: Ming Lei <ming.lei@xxxxxxxxxx>
---
Changes from v1:
* s/quiesced/frozen in commit message
* Added Ming's review tag
block/blk-settings.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/block/blk-settings.c b/block/blk-settings.c
index 896b4654ab00..4dd59059b788 100644
--- a/block/blk-settings.c
+++ b/block/blk-settings.c
@@ -915,6 +915,7 @@ static bool disk_has_partitions(struct gendisk *disk)
void disk_set_zoned(struct gendisk *disk, enum blk_zoned_model model)
{
struct request_queue *q = disk->queue;
+ unsigned int old_model = q->limits.zoned;
switch (model) {
case BLK_ZONED_HM:
@@ -952,7 +953,7 @@ void disk_set_zoned(struct gendisk *disk, enum blk_zoned_model model)
*/
blk_queue_zone_write_granularity(q,
queue_logical_block_size(q));
- } else {
+ } else if (old_model != BLK_ZONED_NONE) {
disk_clear_zone_settings(disk);
}
}
--
2.40.1
